Default Broswer in Oneiric

Since now both Firefox and Chromium have committed to rapid release
schedules, I think it's time to reevaluate the default browser in
Ubuntu. I am concerned that some of these upgrades might break system
integration at some point. While the security team does its best to
prevent regressions, we can't test every case (especially ones we don't
know about :)). Perhaps, if we can find one with sufficient features,
switch to a Webkit based browser with a more normal release schedule (6
months). We could have an installer like Kubuntu does to install
Firefox or Chromium on demand. This will also keep the system
documentation current within the release as the screenshots/menus won't
be out of date shortly after release.